With daytime temperatures hovering in the low nineties and merciless humidity and air pollution bearing down, it takes a lot these days to draw residents of Dhaka, Bangladesh, out into the streets. And that makes the recent demonstrations in the city's Shahbag neighborhood all the more remarkable. For the past several weeks, thousands have rallied in this nondescript area around a single issue: bringing to justice the collaborators who, in early 1971, helped the Pakistani military put down the Bengali nationalist movement in the country's eastern half. That unrest eventually resulted in the late 1971 civil war that led to Bangladesh's establishment as an independent state.

The collaborators were complicit in the genocide of at least one million East Pakistanis, the demonstrators say, and should be tried in court. Many of them belonged to the Islamist party Jamaat-e-Islami, which dates back to when the British ruled the subcontinent and which has always advocated for an Islamic state. During the 1971 war, it cooperated with the Pakistani military regime because its members deemed that the bonds of Islamic solidarity should trump any Bengali nationalist feeling.

The protesters' timing might seem strange, since the demands for justice and a formal ban on the Jamaat are coming well over four decades after the tragic events. But they are part of a struggle over Bangladesh's identity that has raged for decades. The most recent chapter in the story, the trial and sentencing of several Jamaat leaders, began in 2010. That year, Bangladesh's ruling party, the Awami League, set up an International Crimes Tribunal to address 1970s-era war crimes -- a fulfillment of an earlier campaign promise. The tribunal delivered its first verdict in January. Abul Kalam Azad, one leader, was sentenced to death for murder, rape, and arson. Two others, Delawar Hossain Sayedee and Abdul Quader Mollah, were convicted for mass murder. Sayedee received a death sentence and Mollah got life imprisonment.